diff --git a/requirements.txt b/requirements.txt
index 09a1999..cb3d455 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -66,7 +66,7 @@ gym==0.9.6
 h5py==2.7.1
 HeapDict==1.0.0
 hgtk==0.1.1
-html5lib==0.9999999
+html5lib==0.999999999
 idna==2.6
 imagesize==0.7.1
 ipykernel==4.5.2